Products are provided in a broad range of packaging. Both primary packaging—the package containing the product itself, and subsequent packages which contain the primary package are utilized to ensure that the consumer receives the product in the intended usable form.
Packaging may be labeled and/or marked with a variety of indicia to communi to the shopper and the consumer the contents of the package. The source of the product, information regarding the composition of both the product and package may also be provided via package indicia.
In some instances products are coded with information by the product manufacturer to distinguish product lots on the basis of manufacturing site and/or production date and time. Such indicia allow product to be identified throughout the consumer supply chain including after purchase if such identification is necessary.
On-package indicia may be created as the package is produced such as in-mold embossments or debossments. Mold numbers and plastic types are often marked upon plastic packages in this manner. Indicia may be printed upon packages at manufacturing as well. Flexographic and roto-gravure printing may be utilized to print package artwork and information upon the package. Ink-jet coders and laser coders may be utilized to mark the package both at package manufacturing and at the time the package is filled with product. These coders may be utilized late in the overall product manufacturing process to mark production location, date and time of product filling.
Current ink-jet coding equipment is limited in its output by the matrixed nature of the dots the equipment is capable of producing. Typical coder printers may yield characters created from a combination of dots with each possible dot corresponding to a predefined location within a matrix of dots. The relative position of the dots in the matrix can be described by the minimum offset of each dot from its nearest neighbors. The center of each dot is typically offset from its neighbors by at least one dot diameter in each of an x and y directions, as illustrated in FIG. 1. This fixed relationship of the dots and the minimum offset of at least one diameter in two directions reduces the ability of the coder to print curves upon the target surface. The relationship between any dot and its neighbor printed in the adjacent row and column is limited to (at best) being 90 degrees offset (up, down, left and right) or 45 degrees offset. Other angular displacements are not available in the adjacent neighbor dots. The offset between respective dots may be characterized using an x,y coordinate system and providing the offset in each of two directions from an arbitrarily selected origin dot. Known code printers yield dot sets having offsets characterized in terms of multiples of whole dot diameters. As an example, the x offset may be characterized as 1, 2, 3 . . . diameters and the y offset similarly characterized as 1,2,3 . . . dot diameters.
What is desired is a more flexible method for printing a curved set of dots, or a set of dots having differing diameters, upon a package to enable the late stage use of curves in product identification. The invention relates to methods for printing packages at a late product manufacturing stage with curved indicia i.e indicia wherein a set of printed ink dots have at least one nearest neighbor offset at other than 45 or 90 degrees and at a dimensional offset characterised as a non-integer number of dot diameters in at least one direction.